Many light sources use laser pump light to excite and cause a photoluminescent material to emit a luminescence light, which is then collected and used for a further application such as projecting images on a screen. Often such light sources require a large number of laser diodes, whose beams need to be collected and directed onto the photoluminescent material within predetermined etendue limits. Collecting and directing such a large number of laser beams can require numerous reflective surfaces, which can make the optical system bulky and difficult to manufacture and properly align. Moreover, adding additional laser diodes can require corresponding additional reflective surfaces, which can in turn add to the complexity of the optical system as well as increasing the etendue of the light source.
In addition to the challenges of directing the pump light onto the photoluminescent material, collecting and conditioning the luminescence light can also pose challenges. For example, the luminescence light can have a Lambertian profile requiring collection optics to be placed very close to the photoluminescence material in order to efficiently capture the luminescence light. In addition, the collection optics can require additional lenses to condition and/or collimate the luminescence light. However, such collection optics can be in the way of and interfere with the pump light reaching the photoluminescent material.